In the past six months, development of the World Wide Web has begun to fizz thanks to an injection of commercial competition. We’re not talking here about the proliferation of Web sites, but rather the break-neck speed at which browsers are developing. Since the luminaries who wrote Mosaic at the NCSA left to form Netscape Communications last year, they have been striving to differentiate their browser – the Netscape Navigator – from the competition: partly by good coding – the way it loads multiple images concurrently, for example – and partly by supporting proprietary extensions to the Hypertext Markup Language (HTML) which is used to define Web documents’ structure. Netscape extensions to the language leave document designers in something of a quandary: they are very attractive because they give authors much finer control over the look and feel of their pages. The whole history of Web-page construction has been one of people pushing the medium slightly further than it was ever designed to go. With the commercialisation of the Web, this innovation is accelerating. On the other hand, only people running Navigator will actually see the enhancements. Worse, those running other browsers may actually end up seeing a big mess, as their browsers fail to comprehend the commands embedded in the document. Netscape argues that it is simply implementing proposed extensions to the HTML standard, adding that its implementations will change, if necessary, to match the finished HTML 3.0 specification. Last week, the latest draft of HTML 3.0 was published by David Ragget of Hewlett-Packard Laboratories in Bristol, UK – ahead of the WWW conference. HTML 3.0 adds virtually all the facilities included in the latest beta of Netscape, plus a heap of others. It is quite possible that once it is ratified the industry will solidify around it for a time, until the next big thing hits, at which point there will be a rash of new browser releases. But there is still the underlying problem with the Web – implementing something new and exciting requires producing a new browser, and getting it widely accepted. It’s a recipe for fragmentation, confusion and Webs within Webs.


However a new, experimental browser from Sun Microsystems could change all this. HotJava (dreadful name, great idea) had its second Alpha release last week and is the most revolutionary extension to the Web we have seen … ever. People tend to remember the first time they saw the World Wide Web viewed through a graphical browser – their reaction tends to be “Wow”. Java is the first thing we’ve seen that made us go “Wow” on the Web for more than a year. The idea behind HotJava is quite simple – add a complete programming language and build an interpreter into the browser. Do this, and the browser becomes essentially infinitely extensible. The development team have already put up a few simple pages which demonstrate the flexibility of the approach. There is, for example, the page that shows a wire-frame drawing of a helicopter: nothing exciting there, it looks like a straight .GIF, except that if you place your mouse over the picture and drag, you can actually rotate and spin the picture in three dimensions. Other pages have interactive games of Reversi, Hangman and even a simple spreadsheet built in. The site’s home- page has the team’s mascot merrily waving its hand from alongside the HotJava logo. Basically, it seems that virtually anything you can do with a CD- ROM today, you will be able to do with HotJava in the future. You should be able to code a home shopping application or 3D interface, or your very own proprietary communications and encryption system, and anyone with a Java-capable browser will be able to dynamically grab the code and use it. The programs that achieve these effects are termed applets, and are invoked from within standard HTML documents by a single new pseudo-HTML tag, <app>, which is used to invoke the code and pass it parameters: so your HTML document isn’t cluttered up with the full source code for applets. The Java language itself is closely based on C++, but simplified somewhat and with automatic garbage collection added. In addition it has been made so that it is completely architecture neutral, with the quirks of the particular platform being handled by the interpreter. Currently the beta only works on Solaris 2.3, however Mac OS and Win32 ports are being carried out in-house.


There are obvious and scary implications inherent in having lumps of executable code landing on your machine and running without warning. How long until the first Web document with embedded virus appears? The team have incorporated a barrage of security features which attempt to prevent this. The exact details are too long to detail here, but can be found at the project’s Web server at . In brief, the security model is based on interlocking layers of security ranging from features built into from the Java language at the bottom to specific file and network access protections at the top. So, what can you do with HotJava? What can you not? In theory anything you can write as a C++ program can now run in your Web page – no more mucking about with cumbersome shell-script programs running in the /cgi-bin directory. Today there are only a few tiny applets that have been designed as small demos. Once the browser becomes available for commercial use, expect to see the Web transform itself into something quite different. Expect also, C++ programmers to become very popular.

(c) Copyright 1995 Apt Data News Ltd.
London, 17 – 21 April 1995
Issue Number 534, UG534-17
By PowerPC News’ Chris Rose